1. Field of the Invention
This invention relates to a useful anticataract composition. More particularly, the invention relates to a useful anticataract composition containing S-(.alpha.,.beta.-dicarboxyethyl)glutathione, which is a substance found in the body, an ester derivative thereof or a pharmacologically acceptable salt thereof.
2. Description of the Prior Art
Cataract is a disease characterized by an opacification of the crystalline lens owing to various etiologic factors and includes, inter alia, senile cataract and cataract induced by drugs such as steroids.
Aside from the above, a diabetic tends to develop diabetic cataract as a typical complication if his general condition is left uncorrected for a long time. In extreme cases, cataract leads to blindness and requires a surgical intervention for recovery of vision.
Thus far, several anticataract drugs are known for the treatment of cataract due to various causes, such as senile cataract and diabetic cataract, but none have proved to be sufficiently satisfactory in, for example, efficacy.
The inventors of this invention accordingly explored for compounds having superior anticataract activity and found surprisingly that S-(.alpha.,.beta.-dicarboxyethyl)glutathione, which is a physiological substance, and its ester derivatives have very potent anticataract activity. This invention has been conceived and developed on the foundation of the above finding.